1. Field of the Invention
This invention relates to a magnetic recording and reproducing device such as a VTR (video tape recorder).
2. Description of the Prior Art
A magnetic recording and reproducing device is already known which includes a turning force transmission change-over mechanism for alternatively changing over a turning force transmitting condition and a turning force non-transmitting condition in which a driving turning force is transmitted and not transmitted, respectively, to a cassette loading mechanism which, when a cassette is inserted to a predetermined condition into a cassette housing, moves the cassette to a loaded position in which the cassette is fitted on reel shafts of a supply side reel base and a take-up side reel base and which moves, in response to a cassette unloading instruction signal, the cassette from the loaded position to an unloaded position in which the cassette is discharged outwardly of the cassette housing, a tape loading mechanism of drawing out a magnetic tape from within the cassette at the loaded position and extending the same over a predetermined angular range on an outer periphery of a guide cylinder which has a magnetic head thereon, a brake mechanism for selectively applying a braking force to the supply side reel base and the take-up side reel base, a pinch roller driving mechanism for moving a pinch roller into and out of contact with a capstan, a back tension mechanism for selectively applying a resisting force to the supply side reel base and the take-up side reel base to prevent slackening of the magnetic tape, and a rotational speed change-over mechanism for selectively changing a gear ratio to change over the rotational speed of the supply side reel base and the take-up side reel base.
In such a conventional magnetic recording and reproducing device, a plurality of motors and/or some other actuators such as electromagnetic solenoids are provided for each of various mechanisms or for each group of several mechanisms. Accordingly, it is difficult to control operation timings of the mechanisms with a high degree of accuracy, and the magnetic recording and reproducing device is complicated in construction and requires a large number of components and a large number of man-hours for assembly, resulting in a high production cost.
Further, in such a conventional magnetic recording and reproducing device as described above, detecting devices are provided for various mechanisms for detecting their individual operation mode positions. A detection signal from each of the detecting mechanisms is delivered as operation mode position information of the detecting mechanism to an electronic control device which thus controls associated mechanisms to provide for an operation mode which is set at a mode setting section of the magnetic recording and reproducing device. Accordingly, the detecting devices for detecting operation mode positions of the various mechanisms are complicated in construction and occupy a substantial spacing, and the magnetic recording and reproducing device requires a large number of components and a large number of man-hours for assembly, resulting in a high production cost.